High-dynamic-range image recovery from flash and non-flash image pairs

In this paper, we propose a novel method for creating HDR images from only two images-flash and non-flash images. Our method consists of two main steps, namely brightness gamma correction and bi-local chromatic adaptation transform (CAT). The brightness gamma correction performs series of increases and decreases of the non-flash brightness and yields multiple images with various exposure values. The bi-local CAT enhances the quality of each computed image by recovering missing details, using information from the flash image. The final multi-exposure images are then merged together to compute an HDR image. An evaluation shows that our HDR images, obtained by using only two LDR images, are close to HDR images, obtained by combining five manually taken multi-exposure images. Our method does not require the usage of a tripod and it is suitable for images of non-still objects, such as people, candle flames.